Energy-saving permanent magnet roller turbulent air duct cooling structure

Abstract

This application relates to the field of motor technology and discloses an energy-saving permanent magnet drum turbulent airflow cooling structure. The core of this structure lies in constructing a dual-path parallel cooling system consisting of a "rotor heat dissipation cavity" and a "stator convection cavity." Through a first air guide shroud rotating with the drum, the airflow is pre-compressed and accelerated using its internal arc-shaped constricting wall surface. Combined with a specific flow-diverting guide, the airflow is simultaneously injected into the rotor back and the stator core area. The central shaft adopts a "ventilated at both ends, solid in the middle" design, forcing the airflow through the stator heat sink and generating turbulence. This invention solves the problem of heat accumulation caused by the enclosed structure of the external rotor permanent magnet drum. Through a mechanical structure, it achieves automatic air intake, compression, acceleration, and precise flow diversion, significantly reducing winding temperature rise and preventing permanent magnet demagnetization.

Description

Technical Field

[0001] This application belongs to the field of motor technology, specifically relating to an energy-saving permanent magnet drum turbulent air duct cooling structure. Background Technology

[0002] In modern industrial automated conveyor systems, permanent magnet synchronous rollers significantly improve system transmission efficiency and simplify mechanical structure due to their high integration of drive motors and transmission rollers. With continued global investment in energy conservation and environmental protection, high-efficiency energy-saving motors have become a crucial engine for driving the green transformation of the industrial sector. However, as conveyor equipment develops towards wider bandwidth, longer distances, and higher belt speeds, the power density of permanent magnet rollers continues to rise, posing a severe challenge to the internal thermal management system.

[0003] The heat loss inside permanent magnet drums mainly originates from copper and iron losses on the stator side, and eddy current losses on the rotor side due to harmonic magnetic field induction. Because permanent magnet drums typically employ a fully enclosed design to cope with dust and moisture in harsh environments such as mines and ports, their internal heat dissipation faces a severe problem of "heat accumulation." In this enclosed environment, the temperature in the core area often rapidly exceeds the allowable limits for permanent magnet materials such as neodymium iron boron (NdFeB). Once the operating temperature rise approaches or exceeds the Curie point of the material, the magnet will undergo irreversible demagnetization, leading to a sudden drop in motor torque and even paralyzing the entire production line.

[0004] In existing technologies, such as Chinese patent CN207684779U, an attempt is made to use internal and external circulation cooling. However, its internal circulation relies heavily on heat transfer through the drum wall, resulting in an extremely low heat transfer coefficient. Existing air-cooled structures struggle to generate sufficient air pressure at low speeds, and the airflow within the duct is mostly laminar, making it difficult to effectively break down the thermal boundary layer on the solid surface. Furthermore, existing airflow organization paths often lead to dust adhering to the permanent magnets and stator windings, reducing insulation performance and further hindering heat dissipation. Therefore, there is an urgent need for a highly efficient heat dissipation structure that can actively induce turbulence, provide cooling along the entire rotor and stator path, and possess dust-free protection capabilities to meet the pressing need for reliable operation of high-efficiency motors. Summary of the Invention

[0005] This application provides an energy-saving permanent magnet drum turbulent air duct cooling structure to solve the technical problems of difficult heat dissipation, uneven temperature rise, dust affecting lifespan, and poor bidirectional operation stability of existing permanent magnet drums.

[0006] The technical solution adopted in this application is as follows: An energy-saving permanent magnet drum turbulent air duct cooling structure is characterized by comprising: a rotor shell and a permanent magnet rotor located inside it, the permanent magnet being fixed to the inner wall of the permanent magnet rotor, and an annular rotor heat dissipation cavity being formed between the rotor shell and the permanent magnet rotor. A central shaft with an axially arranged ventilation cavity inside and a sealing section in the middle of the central shaft, so that the ventilation cavity forms an air inlet channel and an air outlet channel at both ends of the central shaft, respectively. The stator assembly is fixed on the central shaft and forms a stator heat dissipation cavity between it and the central shaft. The stator heat dissipation cavity is connected to the ventilation cavity through the air passage on the wall of the central shaft. The first air guide shroud is fixed to one side of the rotor housing. The first air guide shroud has an arc-shaped reduced diameter wall surface. The first air guide shroud is equipped with an air inlet keel and a fan assembly. The fan assembly is fixedly connected to the first air guide shroud. The air inlet keel has a circumferential air guide part at the end facing the fan assembly. The second air guide shroud is fixed to the other end of the rotor housing. Inside the shroud is a transfer chamber that communicates with the ventilation chamber. The inner wall of the transfer chamber is provided with a guide wall for smoothing the airflow.

[0007] By adopting the above technical solution, a rotor heat dissipation cavity is formed between the rotor housing and the permanent magnet rotor, and the interior of the central shaft is set as a ventilation cavity running axially through the shaft. Simultaneously, a stator heat dissipation cavity is formed between the stator assembly and the central shaft. These, along with the first and second air guide shrouds forming the air inlet and outlet, create a composite airflow structure within the entire machine, consisting of the rotor heat dissipation cavity, the stator heat dissipation cavity, and the ventilation cavity. This allows the cooling airflow to flow sequentially within multiple cavities, expanding the contact area between the airflow and the heat-generating components, improving heat dissipation efficiency, and reducing localized heat accumulation.

[0008] Optionally, the air inlet keel is provided with a mounting groove at its center, and the mounting groove is connected to the central shaft by a sealed bearing. The air inlet keel rotates synchronously with the first air guide shroud.

[0009] By adopting the above technical solution, an installation groove is set in the center of the air inlet keel, and the installation groove is connected to the central shaft through a sealed bearing, so that the air inlet keel can rotate synchronously with the first air guide shroud. This can improve the rotational stability and coaxiality of the air inlet end, reduce energy loss caused by rotational friction, and reduce the possibility of airflow leakage from the installation joint, thereby improving the overall air guiding efficiency.

[0010] Optionally, the circumferential air guide section has an arc-shaped conical structure to guide the airflow to the rotor heat dissipation cavity and ventilation cavity, thereby reducing the planar wind resistance at the air inlet end.

[0011] By adopting the above technical solution, the circumferential air guide is set as an arc-shaped conical structure, which can concentrate and divert the airflow entering the first air guide shroud, so that the airflow enters the rotor heat dissipation cavity and ventilation cavity more smoothly, reduce the direct impact and turbulent flow at the air inlet, reduce planar wind resistance, and improve airflow utilization.

[0012] Optionally, the fan assembly blades adopt an S-shaped bidirectional airfoil design, so that the air pressure and air volume generated by the rotor housing remain consistent when rotating forward and backward.

[0013] By adopting the above technical solutions, the efficiency of traditional unidirectional curved blades often decreases during reversal, leading to a drop in heat dissipation performance during reverse operation. The S-shaped bidirectional airfoil utilizes the geometric symmetry of the section centerline to ensure that the angle of attack characteristics and lift distribution of the blades are essentially the same in both directions of rotation. This not only ensures the thermal stability of the drum during frequent reversals but also improves the static pressure generation capability at the same rotational speed and reduces flow resistance losses by optimizing the airfoil geometry parameters.

[0014] Optionally, the fan assembly includes at least two symmetrically mounted impellers, one located at the end of the first air guide shroud away from the rotor housing, and the other located at the arc-shaped reduced-diameter wall of the first air guide shroud.

[0015] By adopting the above technical solution, at least two symmetrically installed impellers are arranged at the end of the first air guide shroud furthest from the rotor housing and at the arc-shaped reduced-diameter wall, respectively. This creates a segmented air supply and suction effect, making the airflow distribution in the duct more uniform, improving the fan assembly's air delivery capacity, improving the pressure distribution at the air inlet, and enhancing airflow efficiency. The arc-shaped reduced-diameter wall constitutes a contraction section within the flow channel. Under the premise of equal mass flow rate, the reduction in flow area inevitably leads to a quadratic increase in flow velocity. High-speed airflow has higher momentum, which can more effectively overcome the resistance caused by the complex heat sink array in the stator heat dissipation cavity, enhance the scouring force of the airflow on the solid wall, and thus improve the local convective heat transfer coefficient.

[0016] Optionally, the ventilation cavity includes a first ventilation cavity and a second ventilation cavity, and each ventilation cavity is provided with an air intake part corresponding to the airflow direction, with the end of the air intake part facing the airflow direction having an arc-shaped conical structure.

[0017] By adopting the above technical solution, the ventilation cavity is set as a first ventilation cavity and a second ventilation cavity, and an air-guiding part is set in the ventilation cavity in the direction of airflow. The end of the air-guiding part facing the direction of airflow has an arc-shaped conical structure, which can continuously guide and buffer the airflow in the cavity, reduce the eddy loss of airflow during the turning and diffusion process of the cavity, and improve the continuity and smoothness of internal ventilation.

[0018] Optionally, a number of radially extending heat sinks are evenly distributed circumferentially inside the stator heat dissipation cavity, and the length direction of the heat sinks is consistent with the axial direction of the central shaft.

[0019] By adopting the above technical solution, several radially extending heat sinks are evenly distributed circumferentially in the stator heat dissipation cavity, and the length direction of the heat sinks is aligned with the central axis. This can significantly increase the heat exchange area in the stator heat dissipation cavity, allowing the airflow flowing through this area to fully contact the heat sinks, thereby improving the heat dissipation speed of the stator assembly and reducing the local temperature rise of the stator.

[0020] Optionally, rotor end caps are bolted to both ends of the rotor housing. Several sets of ventilation holes are opened on the rotor end caps and the permanent magnet rotor respectively. The ventilation holes are connected to the rotor heat dissipation cavity. An extension is fixedly provided on the side edge of the rotor end cap near the permanent magnet rotor. A sealing gasket is fixedly connected to the end of the extension. A sealing groove is opened at the ventilation opening on the end face of the permanent magnet rotor to cooperate with the sealing gasket.

[0021] By adopting the above technical solution, rotor end covers connected by bolts are set at both ends of the rotor housing, and corresponding ventilation holes are set between the rotor end covers and the permanent magnet rotor, so that an end air inlet and outlet path is formed inside the rotor, which is conducive to enhancing airflow exchange in the rotor heat dissipation cavity. At the same time, through the cooperation of the extension, sealing gasket and sealing groove, the sealing performance at the end connection can be improved, air leakage can be reduced, the effect of concentrated airflow delivery can be improved, and the reliability of heat dissipation inside the rotor can be enhanced.

[0022] Optionally, a first filter screen and a second filter screen are respectively provided at the air inlet / outlet of the first air guide hood and the second air guide hood. The first filter screen is fixedly connected to the first air guide hood, and the second filter screen is fixedly connected to the second air guide hood through a mounting keel. A sealed bearing is installed at the center of the mounting keel and is rotatably connected to the central shaft.

[0023] By adopting the above technical solution, a first filter screen and a second filter screen are respectively installed at the air inlet and outlet of the first and second air guide hoods. This filters the incoming and outgoing airflow, reducing dust and impurities from entering the cooling channel, mitigating the impact of airflow blockage and internal dust accumulation on heat dissipation efficiency, and extending the equipment's service life. Furthermore, the cooperation between the second filter screen and the mounting frame and sealed bearings improves the filter screen's installation stability and the reliability of the rotation support.

[0024] Optionally, both the first and second air guide covers are provided with air guide cover brackets that can rotate relative to each other, and the end of the central shaft is fixedly connected to a central shaft bracket.

[0025] By adopting the above technical solution, a rotatable air guide cover bracket is set outside the first and second air guide covers, and a central shaft bracket is fixedly connected to the end of the central shaft. This can enhance the installation support strength of the air guide cover and the central shaft, improve the coaxial stability and assembly reliability between the components, and enable the air guide system to maintain good structural stability during rotation, thereby reducing the adverse effects of vibration and sway on airflow organization.

[0026] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows: 1. By separating the rotor heat dissipation cavity from the stator heat dissipation cavity and establishing independent airflow paths for each, zoned heat dissipation of the permanent magnet rotor and stator assembly is achieved, avoiding heat concentration. 2. Through the cooperation of the fan assembly, the arc-shaped reduced diameter wall and the circumferential air guide in the first air guide shroud, the airflow is first accelerated and then split, thereby increasing the effective air volume and flow rate entering the drum. 3. Ventilation chambers are independently set at both ends of the central shaft and connected to the stator heat dissipation cavity through the air vents, so that the stator part has a stable through-type heat dissipation channel. 4. By using S-shaped bidirectional airfoil blades and guide walls, the drum can maintain a relatively stable ventilation capacity during both forward and reverse rotation, adapting to changes in working conditions. 5. By placing the rotor heat dissipation cavity between the rotor housing and the permanent magnet rotor, dust generated by airflow cannot directly contact the internal permanent magnets and stator windings, effectively preventing electronic component failure caused by dust adhesion. Simultaneously, the combination of heat sinks, filters, and the intermediate transfer cavity improves heat exchange efficiency, further reduces impurity entry, and enhances overall energy efficiency and reliability. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a three-dimensional schematic diagram of an energy-saving permanent magnet drum turbulent air duct cooling structure according to this application; Figure 2 This is a cross-sectional view of an energy-saving permanent magnet drum turbulent air duct cooling structure according to this application; Figure 3 for Figure 2 Enlarged view of a portion of point A in the middle; Figure 4 for Figure 2 Enlarged view of a section at point B in the middle; Figure 5 This is an internal mapping diagram in this application; Figure 6 This is a three-dimensional schematic diagram of the fan assembly in this application; Figure 7 This is an assembly drawing of the second filter screen in this application; 1. Rotor housing; 2. Permanent magnet rotor; 3. Permanent magnet; 4. Rotor heat dissipation cavity; 5. First filter screen; 6. Second filter screen; 7. Central shaft; 8. Stator assembly; 9. Ventilation cavity; 91. First ventilation cavity; 92. Second ventilation cavity; 10. Stator heat dissipation cavity; 11. Air outlet; 12. First air guide shroud; 13. Air inlet keel; 14. Peripheral air guide section; 15. Fan assembly; 16. Second air guide shroud; 17. Transfer cavity; 18. Guide wall; 19. Air intake section; 20. Heat sink; 21. Mounting keel; 22. Air guide shroud bracket; 23. Central shaft bracket; 24. Mounting groove; 25. Rotor end cover; 26. Extension section; 27. Sealing gasket; 28. Sealing groove. Detailed Implementation

[0028] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0030] like Figures 1 to 6 As shown, this embodiment provides an energy-saving permanent magnet drum turbulent air duct cooling structure for dissipating and cooling the internal heat-generating components of the permanent magnet drum during forward or reverse rotation.

[0031] The operation of the permanent magnet drum begins with the connection of an external three-phase AC power supply through a connector located at the end of the central shaft 7. A cable extends along a dedicated wiring hole inside the central shaft 7 to the center of the permanent magnet drum, connecting to the windings of the stator assembly 8. The stator assembly 8, supported by the central shaft 7, generates a rotating magnetic field. This magnetic field interacts with the permanent magnets 3 fixed to the outer wall of the permanent magnet rotor 2, producing a strong electromagnetic torque. Since the central shaft 7 is fixed to the ground or conveyor frame via the central shaft bracket 23, the rotor housing 1 begins to rotate according to the principle of reaction force.

[0032] As the rotor housing 1 rotates, the first air guide shroud 12 and the second air guide shroud 16, which are rigidly connected to it by bolts, rotate synchronously at the same angular velocity. This means that the entire external cooling housing and the integrated fan assembly 15 are a single rotating body. At this time, the impeller blades in the fan assembly 15 tangentially cut the air, injecting kinetic energy into the air medium.

[0033] The rotor housing 1 is located on the outermost side and forms the outer rotating part of the permanent magnet drum. The permanent magnet rotor 2 is located inside the rotor housing 1, and an annular rotor heat dissipation cavity 4 is formed between the rotor housing 1 and the permanent magnet rotor 2. The permanent magnet rotor 2 rotates synchronously with the rotor housing 1. Under actual working conditions, the rotor housing 1 drives the permanent magnet rotor 2 to form an external rotating airflow field, so that the airflow entering the cooling structure flows together along the axial and circumferential directions under the induction of rotation, thereby improving the degree of heat transfer disturbance and enhancing the convective heat transfer effect in the rotor heat dissipation cavity 4.

[0034] In this embodiment, rotor end caps 25 are bolted to both ends of the rotor housing 1. Several sets of ventilation holes are correspondingly provided on the rotor end caps 25 and the permanent magnet rotor 2, communicating with the rotor heat dissipation cavity 4. An extension 26 is fixedly provided on the edge of the rotor end cap 25 near the permanent magnet rotor 2, and a sealing gasket 27 is fixedly connected to the end of the extension 26. A sealing groove 28 is provided at the ventilation opening on the end face of the permanent magnet rotor 2, which engages with the sealing gasket 27. This seals the connection between the ventilation holes of the rotor end cap 25 and the ventilation holes of the permanent magnet rotor 2, preventing airflow leakage from the connection point into the drum when airflow enters the rotor heat dissipation cavity 4, effectively preventing electronic component failure caused by dust accumulation.

[0035] Specifically, the first air guide shroud 12 is fixed to one side of the rotor housing 1, and the second air guide shroud 16 is fixed to the other side of the rotor housing 1. After entering the first air guide shroud 12 through the first filter screen 5, the external airflow first gains an initial velocity through the fan assembly 15, then is compressed and accelerated by the arc-shaped narrowed wall surface of the inner wall of the first air guide shroud 12, and subsequently circumferentially guided by the air inlet rib 13 towards the circumferential air guide section 14 formed at one end of the fan assembly 15. At this time, guided by the circumferential air guide section 14, the airflow does not rush directly into the drum, but is split and enters the rotor heat dissipation cavity 4 and the stator heat dissipation cavity 10 respectively.

[0036] During this process, after the extension 26 of the rotor end cover 25 and the sealing gasket 27 are inserted into the sealing groove 28 on the end face of the permanent magnet rotor 2, they can isolate the airflow entry area from the internal space of the drum. That is, when the airflow reaches the connection end between the first air guide shroud 12 and the rotor housing 1, it can only advance forward along the rotor heat dissipation cavity 4 between the inner wall of the rotor housing 1 and the outer periphery of the permanent magnet rotor 2, and will not flow into the drum along the end face sealing gap. With this setting, the airflow entering the rotor heat dissipation cavity 4 forms an annular cooling airflow around the outer periphery of the permanent magnet rotor 2, continuously flushing and dissipating heat from the inner wall of the rotor housing 1 and the permanent magnet rotor 2, while reducing the impact of end air leakage on airflow utilization.

[0037] The central shaft 7 is located on the axis of the rotor housing 1. Structurally, the central shaft 7 is a sealed structure, meaning that the area inside the central shaft corresponding to the stator assembly 8 is a sealed structure. One end of the central shaft 7 forms an air inlet channel, and the other end forms an air outlet channel. With this configuration, the central shaft 7 can serve as both a mounting reference for the stator assembly 8 and an independent airflow channel at both ends, improving airflow utilization.

[0038] The stator assembly 8 is fixed to the central shaft 7, and a stator heat dissipation cavity 10 is formed between the stator assembly 8 and the central shaft 7. The stator windings are wound and installed on the outside of the stator assembly 8. The stator heat dissipation cavity 10 is connected to the ventilation cavity 9 through the air passage 11 on the wall of the central shaft 7. Since the stator assembly 8 is fixed and does not rotate with the rotor housing 1, in actual operation, the airflow entering the interior of the central shaft 7 can enter the stator heat dissipation cavity 10 through the air passage 11, forming a cooling airflow that diffuses axially and circumferentially around the outer periphery of the stator assembly 8 to remove the heat generated during the operation of the stator assembly 8. Especially when heat sinks 20 are provided in the stator heat dissipation cavity 10, the heat sinks 20 extend axially along the central shaft 7 and are staggered circumferentially, which can further increase the airflow disturbance area, extend the flow path of the airflow in the stator heat dissipation cavity 10, and improve the heat exchange efficiency.

[0039] The first air guide shroud 12 is fixed to one end of the rotor housing 1, and the second air guide shroud 16 is fixed to the other end of the rotor housing 1. Both the first air guide shroud 12 and the second air guide shroud 16 are movably connected to the rotor housing 1, preferably by bolt connection, for ease of assembly and maintenance. The first air guide shroud 12 is provided with an air inlet rib 13 and a fan assembly 15. The fan assembly 15 is fixedly connected to the first air guide shroud 12. The air inlet rib 13 is provided with a circumferential air guide part 14 at the end facing the fan assembly 15. The second air guide shroud 16 is provided with a transfer chamber 17 communicating with the ventilation chamber 9. By organizing the air inlet and outlet through the first air guide shroud 12 and the second air guide shroud 16 respectively, a turbulent airflow duct structure with front-to-back flow and branched heat exchange can be formed inside the entire drum.

[0040] In this embodiment, the fan assembly 15 includes at least two symmetrically mounted impellers, preferably a set of symmetrically arranged impeller structures. When the impellers rotate synchronously with the rotor housing 1, they can create an impeller suction and acceleration effect on the airflow entering the first air guide shroud 12, allowing the airflow to first gain initial kinetic energy before entering the subsequent narrowing and diversion areas. The blades of the fan assembly 15 preferably adopt an S-shaped bidirectional airfoil design, so that the rotor housing 1 can form a basically consistent air pressure and airflow when rotating forward and backward. In this way, even if the permanent magnet drum switches directions under different operating conditions, the cooling structure can still maintain a relatively stable ventilation effect, avoiding the problem of uneven heat dissipation caused by the drop in air pressure when the unidirectional blades rotate in reverse.

[0041] The inner wall of the first air guide shroud 12 at the location of the fan assembly 15 is configured as an arc-shaped, narrow-diameter wall. After passing through the fan assembly 15, the airflow cross-section gradually narrows under the guidance of the arc-shaped, narrow-diameter wall, compressing and accelerating the airflow, thereby increasing the flow velocity and dynamic pressure when entering the circumferential air guide section 14. The circumferential air guide section 14 has a conical structure, the function of which is to further rectify the accelerated airflow and distribute it to the outer periphery, so that the airflow forms a split towards the rotor heat dissipation cavity 4 and the ventilation cavity 9 when entering the subsequent space. Because the circumferential air guide section 14 adopts a conical contraction structure, the planar wind resistance at the air inlet end can be reduced, and the airflow can be controllably distributed between the axial and radial directions, reducing local vortex losses.

[0042] The second air guide shroud 16 has a transfer chamber 17 inside, and the inner wall of the transfer chamber 17 is provided with a guide wall 18. The guide wall 18 is used to smooth the airflow direction and prevent the airflow from directly hitting the flat wall surface during reverse operation, thus avoiding separation, backflow, or dead angles. Especially when the drum reverses, the original air inlet and outlet relationship changes. The guide wall 18 can provide a flexible transition for the airflow entering the second air guide shroud 16, so that the airflow can smoothly transition from the transfer chamber 17 to the ventilation chamber 9 or from the ventilation chamber 9 to the transfer chamber 17, thereby maintaining ventilation stability during reverse operation.

[0043] The ventilation chamber 9 inside the central shaft 7 is divided into a first ventilation chamber 91 and a second ventilation chamber 92, which are located on both sides of the central shaft 7 and are set independently of each other. The first ventilation chamber 91 serves as the air inlet channel under forward rotation, and the second ventilation chamber 92 serves as the air outlet channel under forward rotation. Under reverse rotation, the airflow direction of the two switches accordingly, but their respective air intakes 19 still maintain their guiding function.

[0044] An air guide section 19 is provided inside the first ventilation cavity 91, with its conical surface facing opposite to the airflow direction during clockwise rotation. Specifically, when airflow enters the first ventilation cavity 91 from the first air guide shroud 12, the airflow is guided by the conical surface of the air guide section 19, allowing the airflow to smoothly enter the air outlet 11 on the wall of the central shaft 7 and further into the stator heat dissipation cavity 10. In other words, the air guide section 19 in the first ventilation cavity 91 is mainly used to stably guide the airflow entering the first ventilation cavity 91 to the air outlet 11, so that the airflow converges before reaching the stator heat dissipation cavity 10, reducing local disturbances and dead zones caused by direct impact.

[0045] After entering the stator heat dissipation cavity 10, the airflow flows around the outer periphery of the stator assembly 8. The airflow then enters the second ventilation cavity 92 through the air outlet 11 on the other side of the stator heat dissipation cavity 10. A pair of air guides 19 are arranged opposite each other in the second ventilation cavity 92. The air guide 19 on the side closer to the middle of the central shaft 7 is used to guide the airflow during reverse operation, and the air guide 19 on the other side is used to discharge the airflow during forward operation. With this arrangement, when the drum rotates forward, the airflow enters the second ventilation cavity 92 and can smoothly enter the transfer cavity 17 of the second air guide shroud 16 under the action of the air guide 19 on the side away from the middle of the central shaft 7 and finally be discharged. When the drum rotates in reverse, the air guide 19 on the side closer to the middle of the central shaft 7 redirects the airflow entering from the transfer cavity 17, so that it can enter the stator heat dissipation cavity 10 through the second ventilation cavity 92 and the air outlet 11, thereby realizing the intake cooling of the stator part during reverse operation.

[0046] A first filter 5 and a second filter 6 are respectively installed at the air inlet / outlet of the first air guide shroud 12 and the second air guide shroud 16. The first filter 5 is fixedly connected to the air inlet of the first air guide shroud 12, and the second filter 6 is fixedly connected to the air outlet of the second air guide shroud 16 via a mounting frame 21. By setting up the filters, external dust, particles, or impurities can be prevented from entering the drum with the airflow, reducing dust accumulation on the permanent magnet rotor 2, stator assembly 8, and inner wall of the air duct, and reducing heat dissipation attenuation and mechanical wear caused by dust accumulation. The mounting frame 21 provides an installation and support reference for the second filter 6, ensuring that it remains stable under high-speed airflow.

[0047] Furthermore, both the first air guide shroud 12 and the second air guide shroud 16 are equipped with relatively rotatable air guide shroud brackets 22 on their exteriors. These brackets support the overall motor mounting. A sealed bearing is installed at the center of the mounting frame 21 and rotatably connected to the central shaft 7. A central shaft bracket 23 is fixedly connected to the end of the central shaft 7. The central shaft bracket 23 is fixedly connected to the central shaft 7, thus remaining stationary during operation and not rotating with the rotor housing 1. The air guide shroud brackets 22 are located outside the first air guide shroud 12 and the second air guide shroud 16, forming a relative rotational fit with the external mounting components. This structure clarifies the connection between the rotating and stationary parts and facilitates stable support of the air guide shroud ends under different installation conditions.

[0048] Working principle: When an external three-phase AC power supply is connected through the wiring section located at the end of the central shaft 7, the stator assembly 8 supported by the central shaft 7 generates a rotating magnetic field. This magnetic field interacts with the permanent magnet 3 fixed on the outer wall of the permanent magnet rotor 2, generating a strong electromagnetic torque. Since the central shaft 7 is fixed to the ground or conveyor frame through the central shaft bracket 23, the rotor housing 1 begins to rotate according to the principle of reaction force.

[0049] In forward rotation, the rotor housing 1 drives the first air guide shroud 12, the second air guide shroud 16, and the permanent magnet rotor 2 to rotate synchronously. Outside air enters the first air guide shroud 12 through the first filter screen 5, is drawn in and accelerated by the fan assembly 15, and then compressed by the arc-shaped reduced-diameter wall before being guided by the circumferential air guide section 14 to the circumferential inlet at the end of the rotor housing 1. At this time, the rotor end cover 25, the extension 26, the sealing gasket 27, and the sealing groove 28 on the end face of the permanent magnet rotor 2 together form the end sealing boundary, preventing airflow from leaking into the drum. This ensures that the airflow can only enter along the rotor heat dissipation cavity 4 and flow around the outer periphery of the permanent magnet rotor 2, thereby achieving heat dissipation for the rotor housing 1 and the permanent magnet rotor 2. At the same time, another part of the airflow is guided through the first ventilation cavity 91, through the air intake section 19, into the stator heat dissipation cavity 10, flows between the heat sinks 20, and is discharged through the second ventilation cavity 92 to the transfer cavity 17 of the second air guide shroud 16, and is discharged by the second filter screen 6.

[0050] In reverse operation, the airflow direction is reversed accordingly. After entering from one side of the second air guide shroud 16, the air is first smoothly guided by the guide wall 18, and then guided to the stator heat dissipation cavity 10 through the air intake 19 near the solid partition in the second ventilation cavity 92, thereby cooling the stator assembly 8. At the same time, another part of the airflow enters the rotor heat dissipation cavity 4 through the circumferential inlet formed by the second air guide shroud 16 and the end of the rotor housing 1, dissipating heat from the permanent magnet rotor 2. Since the two air intakes 19 in the second ventilation cavity 92 correspond to the forward exhaust and reverse intake states respectively, even if the drum runs in reverse, the airflow can still enter or exit along the predetermined channel, ensuring that the cooling air path maintains a relatively stable ventilation effect under different directions.

[0051] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0052] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0053] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An energy-saving permanent magnet drum turbulent air duct cooling structure, characterized in that, include: The rotor housing (1) and the permanent magnet rotor (2) located inside it, the permanent magnet (3) is fixed to the inner wall of the permanent magnet rotor (2), and an annular rotor heat dissipation cavity (4) is formed between the rotor housing (1) and the permanent magnet rotor (2). A central shaft (7) is provided with a ventilation cavity (9) along the axial direction inside the central shaft (7), and a sealing section is provided in the middle of the central shaft (7) so that the ventilation cavity (9) forms an air inlet channel and an air outlet channel at both ends of the central shaft (7); Stator assembly (8), the stator assembly (8) is fixed on the central shaft (7) and a stator heat dissipation cavity (10) is formed between the stator assembly (8) and the central shaft (7), the stator heat dissipation cavity (10) is connected to the ventilation cavity (9) through the air outlet (11) on the wall of the central shaft (7); The first air guide shroud (12) is fixed to one side of the rotor housing (1). The first air guide shroud (12) has an arc-shaped reduced diameter wall surface. The first air guide shroud (12) is provided with an air inlet keel (13) and a fan assembly (15). The fan assembly (15) is fixedly connected to the first air guide shroud (12). The air inlet keel (13) has a circumferential air guide part (14) at one end facing the fan assembly (15). The second air guide shroud (16) is fixed to the other end of the rotor housing (1), and its interior is provided with a transfer chamber (17) communicating with the ventilation chamber (9). The inner wall of the transfer chamber (17) is provided with a guide wall (18) for smoothing the airflow.

2. The cooling structure according to claim 2, characterized in that: The air intake keel (13) has a mounting groove (24) at its center. The mounting groove (24) is connected to the central shaft (7) through a sealed bearing. The air intake keel (13) rotates synchronously with the first air guide shroud (12).

3. The cooling structure according to claim 3, characterized in that: The circumferential air guide (14) has an arc-shaped conical structure to guide the airflow to the rotor heat dissipation cavity (4) and the ventilation cavity (9) to reduce the air resistance at the air inlet.

4. The cooling structure according to claim 1, characterized in that: The blades of the fan assembly (15) adopt an S-shaped bidirectional airfoil design, so that the wind pressure and air volume generated by the rotor housing (1) remain consistent when rotating forward and backward.

5. The cooling structure according to claim 5, characterized in that: The fan assembly (15) includes at least two symmetrically mounted impellers, one of which is located at the end of the first air guide shroud (12) away from the rotor housing (1), and the other is located at the arc-shaped reduced diameter wall of the first air guide shroud (12).

6. The cooling structure according to claim 6, characterized in that: The ventilation cavity (9) includes a first ventilation cavity (91) and a second ventilation cavity (92). Each ventilation cavity (9) is provided with an air intake part (19) corresponding to the airflow direction. The end of the air intake part (19) facing the airflow direction has an arc-shaped conical structure.

7. The cooling structure according to claim 1, characterized in that: The stator heat dissipation cavity (10) has a number of radially extending heat dissipation fins (20) evenly distributed along the circumference, and the length direction of the heat dissipation fins (20) is consistent with the axial direction of the central axis (7).

8. The cooling structure according to claim 1, characterized in that: The rotor housing (1) is bolted to both ends with rotor end caps (25). The rotor end caps (25) and the permanent magnet rotor (2) are provided with several sets of ventilation holes. The ventilation holes are connected to the rotor heat dissipation cavity (4). The rotor end caps (25) are fixedly provided with an extension (26) on one side edge near the permanent magnet rotor (2). The end of the extension (26) is fixedly connected with a sealing gasket (27). The ventilation opening on the end face of the permanent magnet rotor (2) is provided with a sealing groove (28) that is inserted and matched with the sealing gasket (27).

9. The cooling structure according to claim 1, characterized in that: The first air guide hood (12) and the second air guide hood (16) are respectively provided with a first filter screen (5) and a second filter screen (6) at their air inlets / outlets. The first filter screen (5) is fixedly connected to the first air guide hood (12), and the second filter screen (6) is fixedly connected to the second air guide hood (16) through a mounting keel (21). A sealed bearing is installed at the center of the mounting keel (21) and is rotatably connected to the central shaft (7).

10. The cooling structure according to claim 10, characterized in that: Both the first air guide shroud (12) and the second air guide shroud (16) are provided with air guide shroud brackets (22) that can rotate relative to each other, and the end of the central shaft (7) is fixedly connected to a central shaft bracket (23).

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